RU2766510C2 - Sealed and heat-insulating tank with anti-convection filler - Google Patents

Abstract

FIELD: packing and storage.

SUBSTANCE: group of inventions relates to a sealed and heat-insulating reservoir for storing a fluid. Tank wall comprises an auxiliary heat-insulating barrier, an auxiliary sealing membrane and a main heat-insulating barrier and main sealing membrane supported by main heat-insulating barrier (5). Main insulating elements (6) contain parallelepiped insulating panels arranged so that to provide gap (8) between them. Main heat-insulating barrier (5) additionally contains anticonvection filler (37), located in the gap between the first parallelepiped insulation panel (6) and the second parallelepiped insulation panel. Anticonvection aggregate (37) is made of thin continuous material and has a plurality of elongated wall elements (42), extending substantially over the entire width of the gap to constrain cells extending substantially perpendicular to the thickness direction.

EFFECT: creation of a reservoir limiting availability of continuous circulation channels in heat-insulating barriers for limitation of natural convection in the above heat-insulating barriers.

11 cl, 17 dwg

Description

FIELD OF TECHNOLOGY TO WHICH THE INVENTION RELATES

The present invention relates to the field of sealed and thermally insulated tanks with membranes for storing and/or transporting a fluid, such as a cryogenic fluid.

Sealed and thermally insulated tanks with membranes are particularly used for the storage of liquefied natural gas (LNG), which is stored at atmospheric pressure and at a temperature of approximately -162°C. Such tanks can be installed on land or on a floating structure. In the case of a floating structure, the tank may be designed to transport liquefied natural gas or to receive liquefied natural gas used as fuel to propel the floating structure.

BACKGROUND OF THE INVENTION

In the prior art, sealed and insulated storage tanks for liquefied natural gas are known, the tanks being built into a supporting structure, such as the double hull of a ship intended for the transport of liquefied natural gas. Typically, such tanks comprise a sandwich structure including, in series in the thickness direction from the outside to the inside of the tank, an auxiliary thermal barrier held in the supporting structure, an auxiliary sealing membrane adjacent to the auxiliary thermal barrier, a main thermal barrier adjacent to the auxiliary sealing membrane, and a main sealing membrane adjacent to the main thermal barrier and intended for contact with liquefied natural gas contained in the tank.

WO 2016/046487 discloses a secondary thermal barrier and a primary thermal barrier formed by adjacent insulation panels. In this document WO 2016/046487, the auxiliary seal membrane consists of a plurality of metal sheets containing corrugations protruding towards the outside of the tank and thus allowing the auxiliary seal membrane to deform under the action of thermal and mechanical stresses created by the fluid stored in the tank. The inner surface of the insulating panels of the auxiliary heat-insulating barrier has grooves receiving the corrugations of the corrugated metal sheets of the auxiliary sealing membrane. These corrugations and grooves form a network of channels running along the walls of the tank.

SUMMARY OF THE INVENTION

One of the ideas of the present invention is to provide a sealed and thermally insulating tank with a sealing membrane containing corrugations in which the phenomenon of convection is reduced. In particular, one of the ideas of the present invention is to provide a sealed and thermally insulating reservoir, limiting the presence of continuous circulation channels in thermal barriers to limit the natural convection phenomenon in said thermal barriers.

In accordance with one embodiment, the invention provides a sealed and thermally insulated fluid storage tank, wherein the wall of the tank comprises, sequentially in the thickness direction, an auxiliary thermal barrier including a plurality of adjacent auxiliary insulating elements, wherein the auxiliary insulating elements are held on a load-bearing wall, for example, auxiliary holding components; a secondary sealing membrane supported by secondary sealing members of the secondary thermal barrier, a main thermal barrier including a plurality of adjacent primary sealing members, the primary sealing members being held on the secondary sealing membrane by, for example, primary retaining components; and a main sealing membrane supported by a main thermal barrier and intended to be in contact with the cryogenic fluid contained in the reservoir.

According to embodiments, the reservoir may have one or more of the following features.

In accordance with one embodiment, the auxiliary sealing membrane is a corrugated metal membrane containing a number of parallel corrugations forming channels, in particular very long channels in accordance with the dimensions of the tank, and flat areas located between said corrugations, and the main insulating elements have an external a surface, which may be flat, covering the flats of the secondary seal membrane, and the auxiliary sealing elements have an inner surface, which may be flat, supporting the flats of the auxiliary seal membrane, while in the corrugations of the auxiliary sealing membrane there are anti-convection fill elements that cause pressure losses in the mentioned channels.

Thanks to these distinctive features, it is possible to limit the phenomenon of convection along the corrugations of the auxiliary sealing membrane, in particular in the walls of the tank, which have a vertical or inclined orientation in the gravitational field, and in these walls the temperature gradient between the upper part and the lower part of the wall can contribute to this phenomenon.

In accordance with one embodiment, the corrugations of the auxiliary sealing element protrude towards the outside of the tank in the direction of the supporting structure.

In accordance with one embodiment, the anti-convection fill elements located in the corrugations of the auxiliary sealing membrane are covered with the outer surface of the main insulating elements.

In accordance with one embodiment, anti-convection fill elements located in the corrugations of the auxiliary sealing membrane are attached to the outer surface of the main insulating elements.

In accordance with one embodiment, anti-convection fill elements located in the corrugations of the secondary sealing membrane are fixed, for example, glued, to the secondary sealing membrane.

In accordance with one embodiment, the auxiliary insulating elements have grooves formed in the inner surface for accommodating the corrugations of the auxiliary sealing membrane, and in said grooves between the auxiliary sealing membrane and the auxiliary insulating elements, additional anti-convection filler elements are located, which cause pressure losses in the remaining section of said grooves located around the corrugations of the auxiliary sealing membrane.

In accordance with one embodiment, the corrugations of the secondary sealing membrane protrude into the interior of the reservoir.

In accordance with one embodiment, the anti-convection fill elements located in the corrugations of the auxiliary sealing membrane are supported by the inner surface of the auxiliary insulating elements.

In accordance with one embodiment, the main insulating elements have grooves formed in the outer surface for accommodating the corrugations of the auxiliary sealing membrane, and in said grooves between the auxiliary sealing membrane and the main insulating elements, additional anti-convection filler elements are located, which cause pressure losses in the remaining section of said grooves located around the corrugations of the auxiliary sealing membrane.

In accordance with one embodiment, the main sealing membrane is a corrugated metal membrane containing a number of parallel corrugations forming channels, in particular very long channels in accordance with the dimensions of the tank, and flat areas located between said corrugations, and the main insulating elements have an internal surface supporting the flat portions of the primary sealing membrane.

In accordance with one embodiment, the corrugations of the main sealing membrane protrude towards the outside of the tank in the direction of the supporting structure.

In accordance with one embodiment, the main insulating elements have grooves formed in the inner surface for accommodating the corrugations of the main sealing membrane, and in said grooves between the main sealing membrane and the main insulating elements, additional anti-convection filler elements are located, which cause pressure losses in the remaining section of said grooves located around the corrugations of the main sealing membrane.

In accordance with one embodiment, the anti-convection fill elements comprise an elongated fill located in the corrugation of the auxiliary sealing membrane and/or the main sealing membrane, and the elongated fill has a sectional shape that fills at least 80% of the cross section of the corrugation in the assembled state of the tank and, for example, all sections of the corrugation. The oblong filler element can take on a variety of sectional shapes. For example, the elongated core may take a sectional shape corresponding to the sectional shape of the corrugation, or a circular, elliptical, or other sectional shape.

In accordance with one embodiment, the elongated filler located in the corrugation contains parallel slots oriented across the length of the elongated filler and distributed along the length of the elongated filler.

In accordance with one embodiment, the auxiliary sealing membrane and/or the main sealing membrane comprises a first row of parallel corrugations and a second row of parallel corrugations, which is located transversely to the first row of corrugations, and which intersects the first row of corrugations in the nodal zones, and in the nodal zones of the auxiliary sealing membrane and/or the main sealing membrane elements of the anti-convection filler are located, containing the nodal parts.

In accordance with one embodiment, the anti-convection core element or additional anti-convection core element is made of expanded polystyrene, foamed polymer material or glass wool.

In accordance with one embodiment, the anti-convection core element or the additional anti-convection core element is made of a flexible synthetic material or molded synthetic material.

In accordance with one embodiment, the main insulating elements comprise parallelepipedic insulating panels spaced so as to provide spaces between them, and the main thermal barrier further comprises an anti-convection patch made of a continuous, preferably thin material and located along the edge of the first parallelepipedic insulating panel so that to essentially seal the gap between said first parallelepiped insulating panel and the second parallelepiped insulating panel, wherein the second parallelepiped insulating panel is located adjacent to the first parallelepiped insulating panel, while the anti-convection overlay contains the first edge section located on the inner surface of the first parallelepiped insulating panel.

Thanks to these features, it is possible to limit the phenomenon of convection in the spaces between the parallelepiped insulating panels, in particular in the direction of the tank wall thickness. In particular, such an anti-convection patch can be easily installed even in the case of a narrow gap.

The first edge section of the anti-convection patch can be fixed on the first parallelepiped insulating panel or under the main membrane, in particular glued or clamped on the inner surface of the first parallelepiped insulating panel. The opposite edge of the anti-convection patch preferably remains free.

In accordance with one embodiment, the inner surface of the first parallelepiped insulating panel includes a recess along the gap to receive the first edge portion of the anti-convection patch.

Thanks to these features, it is possible to place and fix the anti-convection pad without affecting the flatness of the inner surface of the parallelepiped insulating panel that supports the sealing membrane.

In accordance with one embodiment, the anti-convection patch bridges the gap between the first parallelepiped insulating panel and the second parallelepiped insulating panel, and the anti-convection patch has a second edge section opposite the first edge section and located on the inner surface of the second parallelepiped insulating panel.

In accordance with one embodiment, the inner surface of the second parallelepiped insulating panel includes a recess along the gap to receive the second edge portion of the anti-convection patch.

In accordance with one embodiment, the width of the first and/or second edge portions is greater than 10 mm.

In accordance with one embodiment, the anti-convection pad comprises a folded portion that enters the gap between the first parallelepiped insulating panel and the second parallelepiped insulating panel, wherein the folded portion comprises a first side extending to the outside in the direction of the thickness of the tank wall from the first edge portion, and the second side extending inward in the direction of the thickness of the tank wall. In this case, the anti-convection patch is preferably made of a flexible material.

According to one embodiment, the folded portion abuts against the side surface of the second parallelepiped insulating panel adjacent to the gap. In this case, the patch need not protrude above the inner surface of the second insulating panel.

In accordance with one embodiment, the length of the anti-convection pad is greater than the length of said edge of the first parallelepiped insulating panel so that it at least protrudes above the third parallelepiped insulating panel, and the third parallelepiped insulating panel is located adjacent to the first parallelepiped insulating panel.

In accordance with one embodiment, the first parallelepiped insulating panel also supports a second anti-convection pad made of a thin continuous material and located along the edge of the first parallelepiped insulating panel, turned towards the third parallelepiped insulating panel, to substantially seal the gap between the said first parallelepiped insulating panel and the third a parallelepiped insulating panel, and the second anti-convection pad contains the first edge section placed or fixed on the inner surface of the first parallelepiped insulating panel.

In accordance with one embodiment, the first and second anti-convection pads are made as a separate piece of thin continuous material, cut in an L-shape.

The anti-convection pad can be made of flexible or rigid materials, for example less than 2 mm thick or less than or equal to 1 mm thick. In accordance with one embodiment, the anti-convection patch is made from a material selected from paper, cardboard, polymer films, composite polymer resin, and fibrous materials.

According to one embodiment, the width of the gap between the first parallelepiped insulating panel and the second parallelepiped insulating panel is less than 10 mm.

In accordance with one embodiment, the main insulating elements comprise parallelepiped insulating panels spaced so as to provide gaps between them, wherein the main thermal barrier further comprises an anti-convection core located in the gap between the first parallelepiped insulating panel and the second parallelepiped insulating panel, the second parallelepiped insulating panel located adjacent to the first parallelepiped insulating panel, wherein the anti-convection core is made of a thin continuous material and has a plurality of elongated wall elements extending substantially across the entire width of the gap to define cells extending substantially perpendicular to the thickness direction.

Thanks to such a filler, it is possible to limit the phenomenon of convection in the spaces between the parallelepiped insulating panels, in particular in the direction of the tank wall thickness. Preferably, the core is made of a relatively flexible material, for example paper, cardboard, plastic film, in particular polyesterimide or polyamideimide, so that the cells can be easily creased and thus adapt to the width of the gap.

The length of the core may be greater than, less than or substantially equal to the length of the edges of the parallelepiped insulating panels between which the gap is formed.

Such a core, in particular, may be discontinuous or may be cut at the location of the main retaining components, at least when the main retaining components are also located in the gaps.

In accordance with one embodiment, the elongated wall elements are formed by successive sections of a sheet of corrugated material having alternating parallel corrugations arranged substantially perpendicular to the thickness direction.

In accordance with one embodiment, the filler has a multilayer structure containing two parallel continuous sheets spaced apart from each other by said elongated wall elements, with the two mentioned parallel continuous sheets located on two side surfaces of the first and second parallelepipedic insulating panels limiting the gap. In such a sandwich construction, the width of the cells is effectively equal to the width of the gap minus the thickness of the two parallel continuous sheets.

According to one embodiment, the elongated wall elements are formed by cylindrical elements extending substantially perpendicular to the thickness direction and secured between two parallel continuous sheets. Cylindrical elements can take any sectional shape, such as hexagonal, round or other shape.

In accordance with one embodiment, at least one of the two parallel continuous sheets spaced apart from each other by said elongated wall elements comprises an upper edge section folded and fixed on the inner surface of at least one of the two parallelepipedic insulating panels, between which is formed interval.

In accordance with one embodiment, the inner surface of the first and/or second parallelepipedic insulating panels includes a recess along the gap to accommodate said upper edge portion of the continuous sheet.

Due to these features, it is possible to position and secure the upper edge portion of the continuous sheet without affecting the flatness of the inner surface of the parallelepiped insulating panel that supports the sealing membrane.

According to one embodiment, the width of the gap between the first parallelepiped insulating panel and the second parallelepiped insulating panel is less than 10 mm.

The tank may be part of an onshore storage facility, e.g. for LNG storage, or may be installed on a floating, offshore or deepwater structure such as an LNG carrier, LNG tanker, FSRU, floating oil production, storage and offloading facility (FPSO), among others.

In accordance with one embodiment, the vessel for transporting cold liquid product contains a double hull and the above tank, located in a double hull.

In accordance with one embodiment, the invention also provides a method for loading or unloading such a vessel, in which fluid is supplied through insulated pipelines from a floating or shore storage to a ship's tank or from a ship's tank to a floating or shore storage.

According to one embodiment, the invention also provides a fluid transfer system, the system comprising the aforementioned vessel, insulated conduits arranged to connect a vessel-mounted tank to floating or shore storage, and a pump for supplying fluid through insulated conduits. from floating or shore storage to a ship's tank, or from a ship's tank to floating or shore storage.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become better understood and additional objects, details, features and advantages will become more apparent from the following description of a number of specific embodiments of the invention, which are given solely by way of non-limiting illustration with reference to the accompanying drawings, in which:

fig. 1 is a cut away perspective view of the wall of a sealed and heat-insulated fluid storage tank;

fig. 2 is a fragmentary perspective view of the section II-II shown in Figure 1 illustrating the first embodiment of the invention;

fig. 3 is a schematic bottom perspective view of an insulating panel of a main thermal barrier according to an alternative embodiment of the first embodiment of the invention;

fig. 4 is a partial perspective view of section II-II shown in FIG. 1 illustrating a second embodiment of the invention;

fig. 5 is a schematic perspective view of an example filler in the form of a filler strip;

fig. 6 is a sectional view illustrating a second embodiment of the invention taken in section III-III of FIG. one;

fig. 7 illustrates a sectional view of a wall of a sealed and thermally insulated tank according to a third embodiment of the invention;

fig. 8 is a schematic partial perspective view of the sealed and heat-insulating tank according to the fourth embodiment, the main sealing membrane is not shown;

fig. 9 is a partial sectional view of the gap between two insulation panels of the main thermal barrier shown in FIG. 7;

fig. 10 is a partial sectional view of the gap between two insulation panels of the main thermal barrier according to the alternative embodiment of FIG. 9;

Figures 11-15 are partial sectional views of the gap between two insulating panels of the main thermal barrier according to the fifth embodiment;

Fig. 16 is a schematic cutaway view of an LNG tanker tank and a tank loading/unloading terminal;

fig. 17 is a schematic representation of the inner plates of three adjacent main insulation panels on which an L-shaped anti-convection pad rests, in accordance with an alternative embodiment of the fourth embodiment of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Conventionally, the expressions "external" and "internal" are used to determine the relative position of one element relative to another, preferably inside and outside the tank.

Fig. 1 illustrates a sandwich wall construction of a sealed and insulated fluid storage tank.

Such a wall of the tank contains from the outside to the inside of the tank an auxiliary heat-insulating barrier 1, including auxiliary insulating panels 2, which are located adjacent to each other and attached to the supporting structure 3 by auxiliary retaining components (not shown), for example, studs welded to supporting structure 3, an auxiliary sealing membrane 4 supported by the auxiliary insulating panels 2 of the auxiliary thermal barrier 1, the main thermal barrier 5, including the main insulating panels 6, which are adjacent to each other and attached to the auxiliary insulating panels 2 of the auxiliary thermal barrier 1 main retaining components 19, and a main sealing membrane 7 supported by the main insulating panels 6 of the main thermal barrier 5 and designed to contact the cryogenic fluid contained in the cut ervoire.

The supporting structure 3 can in particular be a self-supporting metal sheet or, more generally, any type of rigid partition having suitable mechanical properties. The supporting structure 3 can in particular be formed by the hull or double hull of the ship. The supporting structure 3 comprises a plurality of walls defining the overall shape of the tank, generally a polyhedral shape.

Auxiliary insulating panels 2 essentially have the shape of a rectangular parallelepiped. Each auxiliary insulating panel 2 includes an insulating cushion layer 9, for example, an insulating layer 9 of foamed polymer material, located between the inner rigid plate 10 and the outer rigid plate 11. The inner 10 and outer 11 rigid plates are, for example, plywood boards glued to said insulating layer 9 of foamed polymeric material. The insulating foamed polymeric material may in particular be a foamed material based on polyurethane. The foamed polymeric material is preferably reinforced with glass fibers, which helps to reduce thermal shrinkage.

Auxiliary insulating panels 2 are arranged adjacent to each other in parallel rows and separated from each other by gaps 12 providing a functional assembly gap. The gaps 12 are filled with a heat-resistant pad 13 shown in Figures 1 and 7, such as glass wool, rock wool, or flexible open-cell synthetic foam. The heat-resistant spacer 13 is preferably made of a porous material to allow circulation of gas in the spaces 12 between the auxiliary insulating panels 2, for example, circulation of an inert gas, such as nitrogen, within the auxiliary thermal barrier 1, to maintain it in an inert atmosphere and therefore prevent the presence of combustible gas in the range of explosive concentration and/or to place an auxiliary heat-insulating barrier 1 under negative pressure in order to increase the insulating capacity. Gas circulation is also important to facilitate the detection of possible combustible gas leaks. The width of the gap 12 is, for example, approximately 30 mm.

The inner plate 10 has two rows of slots 14, 15 perpendicular to each other to form a network of slots. Each row of grooves 14, 15 is parallel to two opposite sides of the auxiliary insulating panels 2. The grooves 14, 15 are designed to accommodate corrugations 25, 26 protruding to the outside of the tank, formed on the metal sheets 24 of the auxiliary sealing membrane 4. In the embodiment shown in FIG. . 1, the inner plate 10 has three slots 14 extending in the longitudinal direction of the sub-insulation panel 2 and nine slots 15 extending in the transverse direction of the sub-insulation panel 2.

In addition, the inner plate 10 is equipped with metal fastening plates 17, 18 for fixing the edge of the corrugated metal sheets 24 of the auxiliary sealing membrane 4 on the auxiliary insulating panels 2. The metal fastening plates 17, 18 extend in two perpendicular directions that are parallel to two opposite sides of the auxiliary insulating panels 2. The metal plates 17, 18 are fixed to the inner plate 10 of the auxiliary insulation panel 2, for example, with rivets or clips. The metal fastening plates 17, 18 are located in recesses formed in the inner plate 10 so that the inner surface of the metal fastening plates 17, 18 is flush with the inner surface of the inner plate 10. The inner plate 10 has an inner surface that is substantially flat, with the exception of possible separate zones, for example, grooves 14, 15 or recesses for accommodating metal mounting plates 17, 18.

The inner plate 10 is also equipped with threaded studs 19 protruding inside the tank and designed to fix the main thermal barrier 5 on the auxiliary insulating panels 2 of the auxiliary thermal barrier 1. The metal studs 19 pass through the holes provided in the metal mounting plates 17.

The auxiliary sealing membrane 4 includes a plurality of corrugated metal sheets 24, each of which has a substantially rectangular shape. The corrugated metal sheets 24 are positioned offset relative to the auxiliary insulating panels 2 of the auxiliary heat insulating barrier 1, so that each of said corrugated metal sheets 24 is simultaneously located above four adjacent auxiliary insulating panels 2.

Each corrugated metal sheet 24 has a first row of parallel corrugations 25 extending in a first direction and a second row of parallel corrugations 26 extending in a second direction. The directions of the rows of corrugations 25, 26 are perpendicular. Each of the rows of corrugations 25, 26 is parallel to two opposite edges of the corrugated metal sheet 24. The corrugations 25, 26 protrude towards the outside of the tank, i. in the direction of the supporting structure 3. The corrugated metal sheet 24 comprises a plurality of flat surfaces between the corrugations 25, 26. At each intersection between two corrugations 25, 26, the metal sheet 24 includes a nodal zone 27.

The corrugations 25, 26 of the corrugated metal sheets 24 are placed in the grooves 14, 15 formed in the inner plate 10 of the auxiliary insulating panels 2. The adjacent corrugated metal sheets 24 are overlap welded. Corrugated metal sheets 24 are fixed on metal mounting plates 17, 18 with tack welds.

The corrugated metal sheets 24 are made of, for example, Invar® alloy: i.e. the glory of iron and nickel, the expansion coefficient of which is usually from 1.2⋅10 ^-6 to 2⋅10 ^-6 K ^-1 , or an iron alloy with a high manganese content, the expansion coefficient of which is usually approximately 7⋅10 ^-6 K ^-1 . Alternatively, the corrugated metal sheets 24 may also be made of stainless steel or aluminium.

The main thermal barrier 5 comprises a plurality of main insulating panels 6 in a substantially cuboid shape. In this case, the main insulating panels 6 are offset relative to the auxiliary insulating panels 2 of the auxiliary thermal barrier 1, so that each main insulating panel 6 is located above four auxiliary insulating panels 2 of the auxiliary thermal barrier 1. Adjacent main insulating panels 6 are spaced apart from each other by a gap 8, providing functional assembly gap for said main insulating panels 6. However, the gap 8 is smaller than the gap 12 between two adjacent auxiliary insulating panels 2 of the auxiliary thermal barrier 1. Thus, the gap 8 separating the two main insulating panels 6 of the main thermal barrier 5 is approximately 4 mm ± 3 mm.

The main insulating panels 6 have a structure similar to the auxiliary insulating panels 2 of the auxiliary thermal barrier 1, namely, a multilayer structure consisting of an insulating cushioning layer, for example, an insulating layer 29 of foamed polymer material, located between two rigid inner 30 and outer 31 plates, for example, made from plywood. The inner plate 30 of the main insulation panel 6 is equipped with metal fastening plates 32, 33 for fixing the corrugated metal sheets 39 of the main sealing membrane 7, similar to metal fixing plates 17, 18 for fixing the corrugated metal sheets 24 of the auxiliary sealing membrane 4. Similarly, the inner 30 and outer 31 the plates are preferably flat, with the exception of possible separate zones.

The main sealing membrane 7 is obtained by assembling a plurality of corrugated metal sheets 39 similar to the corrugated metal sheets 24 of the secondary sealing membrane 4. Each corrugated metal sheet 39 has two rows of corrugations 40 perpendicular to each other. The corrugations 40 of each of said rows of corrugations 40 are parallel to the respective side of the respective corrugated metal sheet 39. In the embodiment shown in FIG. 1, corrugations 40 protrude into the interior of the tank. The corrugated metal sheets 39 are made of stainless steel or aluminium, for example.

Further details and other embodiments, in particular relating to the secondary 1 and primary 5 thermal barriers, the fixing components of the thermal barriers 1 and 5, and the sealing membranes 4 and 7, can be found in WO 2016/046487, WO 2013/004943 or WO 2014/057221.

In such a tank, the corrugations 25, 26 of the auxiliary sealing membrane 4 form a network of circulation channels. Such channels continuously pass between the auxiliary sealing membrane 4 and the main heat-insulating barrier 5 along the entire wall of the tank. Thus, such channels promote convection movements, in particular in the walls of the tank with a significant vertical component, for example, in the transverse walls of the tank. The network of continuous channels can create thermosyphon phenomena in the main thermal barrier 5. One aspect of the present invention is based on the idea of preventing these convection movements in the tank walls.

Fig. 2 illustrates a fragmentary perspective view of section II-II shown in FIG. 1, at the intersection between the corrugations 25, 26 of the auxiliary sealing membrane 4 according to the first embodiment of the invention. Identical elements or elements that perform the same function as the elements described above are designated by the same reference numerals.

In FIG. 2 shows only two corrugations 25 of the first row of corrugations 25 and two corrugations 26 of the second row of corrugations 26, and these corrugations 25, 26 form nodes 27 of the auxiliary sealing membrane 4 at the intersections. The following description of these corrugations 25, 26 and nodes 27 is equally applicable to all corrugations 25, 26 and all nodes 27 of the auxiliary sealing membrane 4.

One aspect of the present invention is based on the idea of limiting the length of the channels formed by the corrugations 25, 26 of the auxiliary sealing membrane 4. In accordance with the first embodiment of the invention, insulating filler blocks 16 are inserted into one, several or all nodes 27 of the auxiliary sealing membrane 4. These blocks are fillers 16 are located at nodes 27 on the inner surface of the corrugated metal sheets 24 so that they are between the auxiliary sealing membrane 4 and the main thermal barrier 5. In FIG. 2, such filler block 16 is located in each node 27 of the auxiliary sealing membrane 4.

The filler block 16 takes the form of a cruciform insulating block extending into the node 27 into which it is inserted and protruding into the sections of the grooves 25, 26 forming said node 27. In addition, such a filler block 16 has a cross section, the shape of which corresponds to the shapes of the node 27 and sections of grooves 25, 26 into which said filler block 16 is inserted. In the first embodiment, filler blocks 16 are inserted into nodes 27 and sections of the corresponding corrugations 25, 26 after installing the auxiliary sealing membrane 4 on the auxiliary heat-insulating barrier 1 and before installation main insulating panels 6 to the auxiliary sealing membrane 4.

Infill block 16 may be made of any material that provides for pressure loss in the channels formed by corrugations 25, 26. Thus, infill blocks 16 may be made of, for example, foam, felt, glass wool, wood, or other materials.

Preferably, the infill blocks 16 are made of flexible foam material which allows them to be compressed. The flexible foam material makes it possible to design filler blocks 16, the dimensions of which are slightly larger than the dimensions of the nodes 27 and corrugation sections 25, 26, to accommodate the filler blocks 16 in said nodes 27 and corrugation sections 25, 26 with slight compression of the mentioned filler blocks 16 for maximum exact match to the shapes of the node 27.

In addition, the infill blocks 16 are preferably made of open cell foam. The open cell foam makes it possible to limit the phenomenon of convection due to the loss of pressure due to thermal movements inside the channels formed by the corrugations 25, 26, and at the same time allows the circulation of a gas, for example, an inert gas, inside the main thermal barrier 5, as described above for the gasket 13.

Thus, filler blocks 16 form plugs that limit the length of the channels formed by the corrugations 25, 26. As a rule, each corrugation forms a plurality of discontinuous channels, each of which is formed by a section of said corrugation 25, 26 lying between two successive nodes 27. Channels, limited by sections of the corrugations 25, 26 located between two adjacent nodes 27, prevent the occurrence of a significant convection phenomenon, and in particular, prevent the occurrence of a thermosiphon phenomenon.

In embodiments not shown, filler blocks 16 are located only at some nodes 27 and not at all nodes 27. Thus, for example, filler blocks 16 are located at all nodes 27 adjacent to the edges of the corrugated metal sheet 24 forming mentioned nodes 27. In another example, only one node 27 out of two or three along the corrugation 25 and/or 26 is filled with filler block 16.

Fig. 3 is a schematic bottom perspective view of the main insulation panel 6 of the main thermal barrier 5 according to an alternative embodiment of the first embodiment of the invention. Identical elements or elements that perform the same function as the elements described above are designated by the same reference numerals.

In an alternative embodiment of the first embodiment of the invention, the filler blocks 16 are formed by bosses 20 located on the outer surface of the outer plate 31 of the main insulating panels 6, i. on the surface of the outer plates 31 opposite the foam layer 29 of said panels 6. Such bosses 20 are made of any suitable material, for example the materials mentioned above for making the cruciform core block 16. In FIG. The 3 bosses take the form of a cylindrical block of flexible open cell foam. The bosses 20 are attached to the outer plate 31 by any suitable means, such as adhesive, clip, double-sided adhesive tape, or other means. Thus, the step of attaching the bosses 20 to the main insulating panels 6 can advantageously be carried out during the manufacture of said main insulating panels 6, i. e. before making the tank.

The bosses 20 are positioned on the outer plate 31 so that they are inserted into the nodes 27 when the main insulation panels 6 are placed on the secondary sealing membrane 4. Thus, FIG. 3 schematically illustrates corrugations 25, 26 forming a network 21 of corrugations 25, 26 of the auxiliary sealing membrane 4 under the main thermal barrier 5. As shown in FIG. 3, the bosses 20 are located on the outer plate 31 so that each of them is located on the node 27 formed by the intersection of the corrugations 25 and 26 of the auxiliary sealing membrane 4.

Thus, unlike the cross-shaped filler blocks 16 inserted into the nodes 27 before the installation of the main insulation panels 6, as described above with reference to FIG. 2, this alternative embodiment of the first embodiment does not require the step of inserting the core blocks into the nodes 27 and the bosses are directly inserted into said nodes 27 when the main insulation panels 6 are placed in the tank.

Fig. 3 illustrates four spacers 20, each to be inserted into a respective node 27. However, like the filler blocks 16 described above, the number and location of said bosses 20 can be changed to fill all or only some of the nodes 27.

Fig. 4 is a partial perspective view of section II-II shown in FIG. 1 according to the second embodiment of the invention. Identical elements or elements that perform the same function as the elements described above are designated by the same reference numerals.

The second embodiment differs from the first embodiment in that the portions of the corrugations 25, 26 located between two successive nodes 27 are also filled with a heat-resistant gasket. Thus, in addition to the cruciform filler blocks 16 located in the nodes 27, the reservoir contains filler strips 22 located in the areas of the corrugations 25, 26 located outside the nodes 27. Such filler strips 22 can be made of the same materials as which are described above with reference to the cruciform filler blocks 16. Preferably, the filler strips 22 are made of a material that circulates inert gas in the corrugations 25, 26 and at the same time causes a head loss in the thermal circulating flows inside the corrugations 25, 26, preventing the occurrence of a thermosyphon phenomenon due to convection in the mentioned corrugations 25, 26.

Similarly, the filler strips 22 are designed to preferably take on a sectional shape that matches those of the corrugations 25, 26 to block the channels formed by said corrugations 25, 26. The filler strips 22 can also take on other shapes, such as round, compressible under the action of the outer plate 31 of the main insulating panel 6 located above to occupy a significant part of the section of the corresponding corrugations 25, 26, for example, at least 80% of the mentioned corrugation 25, 26.

Thus, in accordance with the preferred embodiment shown in FIG. 5, filler strips 22 are in the form of long strips 5 to 15 cm in length, the section of which corresponds to the full section of the corrugation 25, 26 into which said strip is inserted. This filler strip is preferably made of extruded polystyrene with a density of 8 to 30 kg/m ³ . Ideally, the filler bar has an excess height of 1 to 2/10e mm, due to installation associated with creasing and slight thermal contraction. Preferably, the filler bar also has a serration 49 in its profile so that the head loss it creates with increasing flow rates is significant, and so that the head loss at low speed is limited so as not to completely stop the circulation of gas in the corrugations 25, 26.

Fig. 6 illustrates a sectional view of the corrugation 25 of the auxiliary sealing membrane 4 placed in the groove 14 of the auxiliary insulating panel 2 of the auxiliary thermal barrier, along the section III-III shown in FIG. 1, in accordance with an alternative embodiment of the second embodiment of the invention, which is described with reference to FIG. 4. Identical elements or elements that perform the same function as the elements described above are designated by the same reference numbers. In addition, the following description with reference to FIG. 6 for a corrugation 25 placed in a groove 14 is equally applicable to one or more other grooves 14 and/or 15.

As shown in FIG. 6, the groove 14 extends completely through the thickness of the inner plate 10 and extends into the foam layer 9. The groove 14 is designed to provide a gap for placing the corrugation 25 in the said groove 14 when the corresponding corrugated metal sheet 24 is installed on the auxiliary insulating panel 2 containing the mentioned groove 14. This gap should also allow relative movements between the corrugation and the walls of the groove 14, which arise due to differences in compressions and expansions.

Since the corrugations 25, 26 form a network of channels that contribute through convection to the occurrence of a thermosyphon phenomenon in the main thermal barrier 5, the grooves 14, 15 form a network in the auxiliary thermal barrier 1, also forming a network of channels that can be the source of such a thermosyphon phenomenon due to convection.

To prevent this phenomenon, the alternate embodiment of the second embodiment is different from the alternate embodiment described with reference to FIG. 4, in that it contains, in addition to filler blocks 16 in nodes 27 and filler strips 22 in corrugations 25, 26, a third filler block 23 located in grooves 14, 15 of inner plates 10 of auxiliary insulating panels 2.

As shown in FIG. 6, the third filler block 23 is located in the grooves 14 which cause pressure losses during the circulation of cold in the network formed by the grooves 14, 15. The third filler block 23 is similar to the filler block 16 and the filler strip 22 and can be made of various materials. Preferably, this padding is made of flexible open cell foam so as not to prevent circulation of inert gas and/or detection of leaks in the auxiliary thermal barrier 1. The third filler block 23 is installed in the groove 14 before installing the corresponding corrugated metal sheet 24.

Preferably, the third filler block 23 is compressible and is compressed by the corrugation 25 of the corrugated metal sheet 24 to ensure proper distribution throughout the groove 14. In particular, it is preferred that highly deformable materials (Ultra High Density Styrofoam (<10 kg/kg) are used for the third filler block 23. m ³ ), melamine foam, low density flexible polyurethane foam) that collapse when the corrugated metal sheet 24 is installed. groove 14 immediately prior to the installation of the corrugated metal sheet 24, the corrugation of which is to be placed in said groove 14.

Fig. 6 illustrates the use of a third filler block 23 in the corrugation 25 of the secondary metal sheet 24. protruding to the outside of the tank and placed in the corresponding grooves formed in the inner plates 31 of the main insulating panels 6, the third filler block 23 can be used in a similar way to fill the channels formed by said grooves formed in the inner plate 31 of the main insulating panels 6.

Fig. 7 illustrates a sectional view of a wall of a sealed and thermally insulated tank according to a third embodiment of the invention. Identical elements or elements that perform the same function as the elements described above are designated by the same reference numerals.

The third embodiment differs from the second embodiment in that the corrugations 25, 26 of the secondary sealing membrane 4 as well as the corrugations 40 of the main sealing membrane 7 are inwardly directed corrugations, i. protruding into the tank. Thus, the grooves 14, 15 containing the corrugations 25, 26 of the auxiliary sealing membrane 4 are formed in the outer plates 30 of the main insulating panels 6. In this regard, the filler block 16 and the filler strip 22 are located between the corrugated metal sheets 24 and the inner plates 10 auxiliary insulating panels 2. In addition, the third filler block 23 is placed in the grooves 14, 15 made in the outer plates 30 of the main insulating panels 6 between the said main insulating panels 6 and the corrugations 25, 26 of the auxiliary sealing membrane 4.

In addition, as shown in FIG. 7, filler block 16 and filler strip 22 can also be located under the corrugations 40 of the main sealing membrane 7 between said corrugations 40 and the inner plate 31 of said main insulating panels 6. In the holes formed at the corners of the main insulating panels 6 to accommodate fastener components 19, an insulating gasket 51 can also be located. As in the previous embodiments, it is possible to install a filler block in all or only some nodes and / or corrugations of the auxiliary 4 and / or main 7 sealing membrane and / or grooves containing said corrugations.

Fig. 8 is a fragmentary perspective view of the sealed and heat-insulated tank with the main sealing membrane omitted, according to the fourth embodiment. Identical elements or elements that perform the same function as the elements described above are designated by the same reference numerals.

In FIG. 8 the gap 8 between the two main insulating panels 6 is shown by dotted lines 28. Like the corrugations 25, 26 and the grooves 14, 15, the gaps 8 between the main insulating panels 6 form a network that creates circulation channels that circulate cold through convection towards the auxiliary sealing membrane 4 and causing the occurrence of a thermosiphon phenomenon unfavorable for the insulation of the tank wall, in particular due to the fact that the main sealing membrane 7 in contact with the LNG contained in the tank is supported by said main insulation panels 6.

The invention in accordance with the fourth embodiment provides for the installation of anti-convection pads 34 located between adjacent main insulating panels 6 along the gap lines 8 between said adjacent main insulating panels. Such anti-convection pads 34 can be made from a variety of materials. Preferably, the anti-convection pads are made from continuous non-porous or low-porous materials. Thus, anti-convection pads 34 are, for example, films made of paper, cardboard, or even synthetic, plastic or other films. Such anti-convection pads can be located in correspondence with all gaps 8 as shown in FIG. 8, or only with some of the mentioned gaps 8.

With reference to FIG. 9, the anti-convection patch 34 is located along the main insulation panels 6 along the gap lines 8 between said main insulation panels 6. The inner edge of the inner plate 31 of said main insulation panels 6 contains a recess 35 in which the corresponding edge 36 of the anti-convection patch 34 is placed, so that the anti-convection patch 34 is flush with the inner surface of said inner plate 31. Thus, the anti-convection pad 34 covers the gap 8 and separates the gap 8 from the main sealing membrane 7, preventing the formation of channels with different temperatures that can cause a thermosiphon phenomenon in the network formed by the gaps 8 of the tank wall .

Preferably, the anti-convection pad is made of a sealed material with a thickness of 0.2 mm to 2 mm. This sealed material is, for example, a plastic material (PEI, PVC, etc.), cardboard, thick laminated paper or other material.

The width of the anti-convection pad 34 is chosen such that the anti-convection pad 34 rests in the recesses 35 on a minimum bearing surface, for example, at least 10 mm, for any compression of the inner plates 31 and said anti-convection pad 34. In other words, the anti-convection pad 34 is designed so that its the edges 36 are located in the recesses 35, including when the tank is filled with LNG. In this regard, one of the edges 36 of the anti-convection pad may partially protrude from the recess 35, covering the inner plate 31 outside of the recess 35 to ensure that said edge 36 remains placed in the recess in a compressed state. The edges 36 of the anti-convection pad 34 are clamped or glued to one of the two main insulation panels 6 in the recess 35.

As shown in FIG. 8, the main thermal barrier 5 comprises a plurality of cover plates 38 terminating the bearing surface of the main sealing membrane 7 near the holes for accommodating fasteners 19 of the main thermal barrier 5. Because these holes are located in the continuation of the gaps 8 between the main insulation panels 6, the anti-convection strips 34 may be interrupted. on said cover plates 38. Preferably, in this case, anti-convection pads 34 are connected to said cover plates 38 to limit the presence of passages between the main sealing membrane 7 and the gaps 8. Preferably, anti-convection pads 34 and cover plates 38 are flush with the inner plates 31 of the main insulating panels 6, forming a continuous flat surface for the main sealing membrane 7.

In an alternative embodiment, which is not shown, the anti-convection pads 34 at least partially cover the cover plates 38. 34 are flush with the inner plates 31 of the main insulation panels 6.

In another alternative embodiment, the anti-convection pads 34 are continuous and completely cover the cover plates 38. Preferably, the anti-convection pads 34 are flush with the inner plates 31 of the main insulation panels 6.

In another preferred alternative embodiment, the anti-convection pads 34 are continuous and completely cover the cover plates 38. Preferably, the anti-convection pads 34 are flush with the inner plates 31 of the main insulation panels 6, including when they pass over the cover plates 38.

In another alternative embodiment, shown schematically in FIG. 17, the anti-convection pads 34 take on an "L" shape, i. e. one anti-convection pad 34 covers the two joint edges of the inner plate 30 of one main insulation panel 6 and is therefore located along the gap lines 8 formed by said main insulation panel 6 and two adjacent main insulation panels 6. Thus, the inner plates 31 of the main insulation panels 6 accommodate two anti-convection pads so that all gaps 8 are successively blocked.

In an alternative embodiment of the fourth embodiment shown in FIG. 10, the anti-convection pad 34 is curved so that the central portion 41 of the anti-convection pad 34 connecting the two folded edges 36 is located in the gap 8 separating adjacent main insulation panels 6. Alternatively, the second edge of the anti-convection pad 34 may be supported along the side surface of the second the main insulating panel 6 without leaving the gap 8.

Figures 11-15 illustrate various alternative embodiments of the fifth embodiment of the invention.

The fifth embodiment differs from the fourth embodiment shown in Figures 8-10 in that the anti-convection pad 34 is replaced by an anti-convection filler 37 placed in gap 8. Elements that are identical or perform the same function as the elements described above are indicated by those same reference positions. The anti-convection core is preferably compressible. The anti-convection core is inserted into the gap 8 between the main insulation panels 6 after said main insulation panels 6 are installed on the auxiliary sealing membrane 4. In this regard, the anti-convection core is, if necessary, compressed in thickness to be inserted between the main insulation panels 6, possibly forcibly.

Anti-convection fill 37 can be obtained in many ways. In one embodiment, the anti-convection filler 37 may be made of a porous material forced into the gap 8 to provide significant prestressing to allow the dimensions of the gap 8 to be filled to be varied. The anti-convection filler 37, made of a porous material, is particularly suitable for large gaps 8, for example from 10 mm to 100 mm. The porous material may be glass wool, for example ideally composed of superimposed layers.

However, as described above with reference to FIG. 1, the gap 8 between the two main insulation panels 6 can be relatively narrow, typically about 4 mm ± 3 mm. Such a limited gap cannot be reliably filled by inserting a very thin insulating pad, unlike the gap 12 between the auxiliary insulating panels 2. Moreover, the roughness of the main insulating panels 6 can damage the very thin insulating padding material when inserted. Roughness, among other things, is associated with the presence of glass fibers in the insulating layer 29 of the foamed material of the main insulating panels 6. Thus, in the preferred solution, sheets of sealed materials (not shown) are added between the layers of glass wool to separate the total volume of anti-convection core 37 into separate layers that experience only slight thermal gradient and having sufficient resistance to allow insertion of the anti-convection filler 37 without damaging the gap 8.

Fig. 11 illustrates an embodiment of an anti-convection core 37. The anti-convection core 37 is of a sandwich construction including a compressible center portion 42. Thus, in FIG. 11 illustrating an embodiment of the fifth embodiment, the anti-convection filler 37 comprises two sheets 43 each containing a folded edge 44 placed in a corresponding recess 35 of the main insulation panels 6. The folded edge 44 is clamped in the recess 35 which allows said folded edges 44 to remain in recesses 35 even during resizing of the gap 8 between the main insulating panels 6, for example during compression associated with LNG supply to the tank.

Each sheet 43 is located in the gap 8 between the main insulation panels 6 along said main insulation panels 6 from the recess 35 towards the auxiliary sealing membrane 4. The two sheets 43 are connected by a compressible central section 42 placed in the gap 8 between the main insulation panels 6. the compressible center section 42 is made of sealed materials, such as plastic material (PEI, PVC, etc.), cardboard, thick laminated paper, or other material. In this way, the sheets 43 and the compressible center portion 42 can be inserted along the main insulation panels 6 without being damaged due to the roughness of said panels 6 even in the case of a narrow gap 8.

The compressible center section 42 of the anti-convection core 37 can be made in a variety of ways. In the example shown in figures 11 and 12, the compressible central portion 42 has a honeycomb structure consisting of a number of cells located along each of the sheets 43 in the gap 8 between the main insulating panels 6, with each cell 44 attached to the two mentioned sheets 43 for constructive connections of said sheets 43. Other examples of compressible central portions 42 are shown with reference to Figures 13 and 14.

Figures 12-13 illustrate an alternative embodiment of the anti-convection core 37. The alternative embodiment is characterized in that the sheets 43 of the anti-convection core 37 do not include a folded edge 44, and in that the main insulation panels 6 do not include a recess 35. Thus, the anti-convection core 37 itself placed and passes in the gap 8 between the main insulating panels 6.

In the example shown in FIG. 13, the compressible central portion 42 is formed by a plurality of tubes 46 separating the two sheets 43 and extending in the gap 8 along the main insulation panels 6.

In the example shown in FIG. 14, the compressible central portion 42 consists of a plurality of spacers 47 located between two sheets 43 and delimiting a plurality of rectangular cells 48 extending in the gap 8 along the main insulation panels 6.

Fig. 15 illustrates an alternative embodiment of the anti-convection core 37. An alternative embodiment is characterized in that the anti-convection core 37 is not a sandwich structure, but is a single corrugated sheet 45. The corrugated sheet 45 divides the gap 8 between the main insulation panels 6 into a plurality of cells continuously extending along mentioned panels 6.

The contour shape of the main insulating panels 6 and the auxiliary insulating panels 2 described above is generally rectangular, but other contour shapes are possible, in particular hexagonal shapes for covering flat walls, or suitable contour shapes, which may alternatively be uneven, to cover specific areas of the tank.

With reference to FIG. 16 is a cutaway view of an LNG tanker 70 illustrating a sealed and insulating tank 71, having a generally prismatic shape, mounted in a double hull 72 of the vessel. The tank wall 71 includes a main seal membrane for contact with the LNG contained in the tank, an auxiliary seal membrane located between the main seal membrane and the double hull 72 of the vessel, and two insulating barriers, respectively, located between the main seal membrane and the auxiliary seal membrane and between auxiliary sealing membrane and double housing 72.

In a substantially known manner, loading and unloading pipelines 73 located on the upper deck of the vessel can be connected by appropriate connectors to a sea or port terminal for supplying LNG to or from tank 71.

Fig. 16 illustrates an example of an offshore terminal comprising a loading and unloading station 75, a subsea pipeline 76, and an onshore facility 77. The loading and unloading station 75 is an offshore fixed structure containing a movable boom 74 and a tower 78 that supports the movable boom 74. The movable boom 74 supports a bundle of insulated flexible hoses 79 that can be connected to the loading and unloading pipelines 73. The orientable mobile boom 74 can be adapted to LNG tankers of all shapes. Inside the tower 78 is a connecting pipe, which is not shown. Loading and unloading station 75 allows the loading and unloading of the vessel 70 from the onshore facility 77, which contains tanks 80 for storing liquefied gas and connecting pipes 81 connected by an underwater pipeline 76 to the loading and unloading station 75, and vice versa. The subsea pipeline 76 allows the transfer of liquefied gas between the loading and unloading station 75 and the onshore facility 77 over long distances, for example, 5 km, which allows the LNG tanker 70 to be stopped far from the coast during loading and unloading operations.

Pumps on board the ship 70 and/or pumps installed at the shore facility 77 and/or pumps installed at the loading and unloading station 75 are used to create the pressure necessary for the transfer of liquefied gas.

Although the invention has been described in relation to a variety of specific embodiments, it is clear that it is not limited to them in any way, and that it contains all technical equivalents of the described means, as well as combinations thereof, if they are within the scope of the invention, which is defined by the claims.

The use of the verb "comprise" or "include" and derivative forms does not exclude the presence of other elements or other steps other than those mentioned in the claim.

In the claims, no parenthesized reference numeral may be interpreted as limiting the claim.

Claims (13)

1. A sealed and heat-insulating tank for storing fluid, and the flat wall of the tank contains sequentially in the thickness direction an auxiliary heat-insulating barrier (1) containing a plurality of adjacent auxiliary insulating elements (2), the auxiliary insulating elements being held on the bearing wall (3), the auxiliary a sealing membrane (4) supported by auxiliary insulating elements (2) of an auxiliary heat-insulating barrier (1), a main heat-insulating barrier (5) containing a plurality of adjacent main insulating elements (6), with the main insulating elements being held on the auxiliary sealing membrane (4), and a main sealing membrane (7) supported by a main thermal barrier (5) and designed to come into contact with the cryogenic fluid contained in the tank, in which the main insulating elements (6) contain flat parallelepipedic insulating panels arranged so as to form gaps (8) between them, moreover, the main heat-insulating barrier (5) additionally contains an anti-convection filler (37) located in the gap between the first flat parallelepiped insulating panel (6) and the second flat parallelepiped insulating panel, while the second parallelepiped insulating panel is located adjacent to the first parallelepiped insulating panel, and anti-convection the filler (37) is made of a thin continuous material and has a plurality of elongated wall elements (42, 45, 46, 47) extending substantially across the entire width of the gap to delimit cells (48) extending substantially perpendicular to the thickness direction. 2. A container as claimed in claim 1, wherein the elongated wall elements are formed by successive portions of a sheet (45) of corrugated material having alternating parallel corrugations extending substantially perpendicular to the thickness direction. 3. The tank according to claim 1 or 2, in which the filler has a multilayer structure containing two parallel continuous sheets (43) spaced apart from each other by the specified elongated wall elements (42, 45, 46, 47), and the two mentioned parallel continuous sheets (43) are located on two side surfaces of the first and second parallelepipedic insulating panels, limiting the gap (8). 4. A container according to claim 3, wherein the elongated wall elements are formed by cylindrical elements (42, 46) extending substantially perpendicular to the thickness direction and fixed between two parallel continuous sheets. 5. The tank according to claim 3, in which at least one of the two parallel continuous sheets (43), spaced apart from each other by the mentioned elongated wall elements, contains an upper edge section (44), bent and fixed on the inner surface of at least one of two parallelepiped insulating panels (6), between which a gap is formed. 6. The tank according to claim 5, in which the inner surface of the first and/or second parallelepiped insulating panels (6) contains a recess (35) along the gap to accommodate said upper edge section (44) of the continuous sheet. 7. The tank according to any one of paragraphs. 1-6, in which the width of the gap (8) between the first parallelepiped insulating panel and the second parallelepiped insulating panel (6) is less than 10 mm. 8. The tank according to any one of paragraphs. 1-7, in which the anti-convection filler (37) is made of a flexible material so that the cells can easily collapse in the direction of the width of the gap. 9. Vessel (70) for transporting a fluid containing a double housing (72) and a tank (71) according to any one of paragraphs. 1-8, located in a double housing. 10. A fluid transmission system comprising a ship (70) according to claim 9, insulated pipelines (73, 79, 76, 81) located so as to connect a tank (71) installed in the ship's hull with floating or shore storage ( 77), and a pump for supplying fluid through insulated pipelines from the floating or shore storage to the ship's tank or from the ship's tank to the floating or shore storage. 11. The method of loading or unloading a ship (70) according to claim 9, wherein the fluid is supplied through insulated pipelines (73, 79, 76, 81) from a floating or shore storage (77) to a tank (71) of a ship or from a ship tank to floating or shore storage.

Images